Loud speaker



Patented Dec. 22, 1925.

UNITED STATES PATENT OFFICE.

MAURICE C. BYPIIN SKI,

MENTS, TO BRANDES PORATION OF NEW JERSEY.

LOUID SPEAKER.

Application filed March 4, 1925. Serial No. 13,008.

To all whom it m concem:

Be it known that I, MAURICE G. Rrrmsm, a citizen of the United States, residing at Yonkers, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Loud Speakers, of which the following is a specification.

My invention relates broadly to electromagnetic sound reproducers and more particularly to a construction of loud speaker for reproduction in radio broadcast reception. One of the objects of my invention is to provide a construction of loud speaker 16 in which the tone sound is greatly improved over the qualities heretofore possessed by other loud speakers.

Another object of my invention is to provide a construction of loud speaker having a plurality of concentrically positioned diaphragms of difiering natural periods operated simultaneously from the same .electromag netic operating mechanism for reproducing sound efficiently over a broad range of tone frequencies.

Still another object or my invention is to provide a construction of electromagnetic sound reproducer in which a plurality of diaphragms are conveniently arranged within a relatively small area and actuated by the same electromagnetic driver, one of the diaphragms operating to reproduce sound over a frequency scale at which another of saiddiaphragms may be relatively ineflic'ient, while another of said diaphragms opcrates to reproduce sound efliciently over a range of notes at which the first mentioned diaphragm may be relatively inefficient; resulting in the integration of efficiently reproduced tone quality of vnotes overv the en tire range of frequencies.

My invention will he stood from the specification hereinafter I found, by reference to the accompanying drawings, in which:

Figure 1 is a cross-sectional view of the loud speaker, constructed in accordance with my invention;

Fig. 2 is a plan view taken A-Abf Fig. 1; and. I

Fig. 3 is a plan view of one of the diamore fully underalong the line quality of the reproduced d phragms used in the loud speaker of my invention.

Heretofore in the art, it has been proposed to employ a plurality of independent telephone receiver units for the reproduction of sound and deliver the reproduced sound to a central amplifying horn. This arrangement for telephone receiver units, when applied to loud speaker construction, has not 0 been .desirable either from the point of view of manufacture and production or from the viewpoint of securing efficient reproduction of signals. By my invention, I provide a construction of electromagnetic sound reproucer in which the same electromagnetic operating mechanism is employed in actuating diaphragms having differing natural eriods. Diaphragms of relatively different iameters are employed and in one of the 7 diaphragms apertures are provided through WhlCll extended portions of the polev pieces of the electromagnetic operating mechanism protrude to a position where a diaphragm of relatively smaller size may be actuated and the diaphragms being each efficient over a particular range of notes enables the received energy to be faithfully reproduced at good tone quality.

Referring more particularly to the drawings, reference character 1 designates a casing in which the electromagnetic operating mechanism is housed. The casing 1s screwthreaded at 2 near its upper extremity and is provided with a perlpheral flat edge 3 forming a seat for the sound reproducin diaphragm 4. The diaphragm 4 is secured in position by the circular member -5, pins 6 being positioned between the circular member 5 and the casing 1 and fitting in notches 6 formed in the diaphragm 4. A cap member 7 is screw-threaded upon the screw-threads 2 on casing 1 in such manner that the annular skirt 8 on the cap 7 embraces the sides of the casing l. The cap portion? is screw-threaded at its central portion as indicated by reference character 9 and carries a ferrule 10 formin a support for an acoustic horn 11. The entire unit may be suitably supported from any desired surface by means of machine screws passing into the screw threaded bores 12.

The electromagnetic mechanism is carried by a permanent magnetic member 14 having a. central stem 15 extending from the rear thereof and passing through the casing 1. The stem 15 is screw-threaded at its extremity as represented at 16 permitting an adjustable nut 18 to be revolved upon the screw-threads 16 to retract the stem 15 against the action of the spring 17. The terminals for the electromagnetic system are represented at 20 secured in the rear wall of the casing. The magnetic angle members 21 and 22 are secured on the adjustable frame of the electromagnetic operating mechanism and carry the bobbins 23 and 24. The an gles 21 and 22 extend upwardly and are provided with shoulders 25 and 26 which form pole faces and operate'upon the'magnetic diaphragm 4. Th magnetic diaphragm 1 is slotted or apertured as indicated at 33 and 34, permitting extended portions 27 and 28 of the magnetic angles 21 and 22 to extend therethrough and through apertures 30 in a supplemental sound reproducer casing 32. The supplemental sound reproducer casing 32 has a depth related to the size of the diaphragm 31 while the depth of the main casing 1 is correspondingly related to the diameter of the diaphragm 4E. The xtended portions 27 and 28 pass through the rear wall of the supplemental sound reproducer casing 32 to a position in proximity to the diaphragm 31. The supplemental sound reproducer casing 32 is supported by spider members 35, 36 and 37 from the ring memher 5 to a central position within the sound reproducer casing 1.' The diaphragm 31 is proportioned with respect to the diaphragm 4 in such manner that the integrated tone quality of the reproduced sound is greatly improved over that heretofore obtainable. That is to say, diaphragm 31 reproduces efficiently those tones for which diaphragm 4 is inefficient, while diaphragm 4 reproduces efficiently those tones for which diaphragm 31 is a relatively inefficient reproducer. The sound reproduced by both diaphragms 31 and 4: is delivered to the acoustic horn represented as having an inlet at 11.

In the operation of the electromagnetic sound reproducer it will be observed that by adjusting the rotatable nut 18 a position may be selected at which the gaps between the shoulders 25 26 of the magnetic members 21 and 22 will efficiently co-operate with diaphragm 1 and at the same time the gap between the extremities of the extended portions 27 and 28 "will efficiently cooperate with diaphragm 31. The magnetic gaps between the pole faces and each of the diaphragms may be regulated at the will of the operator in order to receive and reproduce energy of varying amplitudes. The origin of the sound waves from each acoustic member 4 and 31 is practically at. the same point so that my construction avoids interference we es due to interaction of the separately produced sound waves. Heretofore where independent sound reproducing units have been provided separated at a substantial distance one from the other, there has been a tendency for the sound waves to interfere by reason of their phase relationship. At certain frequencies the waves might be 180 degrees out of phase and these frequencies therefore would be annulled and would not be reproduced. 'This is not the case however where the sound waves are in perfect original time phase due to being produced by one electromagnetic system, the waves starting from approximately th same point in the horn.

While I have described my invention in a certain particular embodiment, I desire it to be understood that modifications can be made and that the invention as disclosed herein is to be considered in the illustrative rather than the limiting sense. For example, the diaphragms 4: and 31 may take the form of cones in one or separate chambers, or, a rod or reed might be used as the sound reproducing member, but in all cases the same electromagnetic system would be employed and connections between the operating armature provided through one of the sound reproducing members.

What I claim and desire to secure by Letters Patent of the United States, is as follows:

1. An electromagnetic sound reproducer comprlsing in combination a. main casing forming a chamber, a diaphragm closing one end of said chamber, an electromagnetic operatlng mechanism carried within said chamber and arranged to actuate said diaphragm, a supplemental chamber supported from said mam casing, a diaphragm carried within said supplemental chamber, and means whereby said electromagnetic operating mechanism operates each of said diaphragms for reproducing sound over a broad range of tone frequencies.

2. An electromagnetic sound reproducer comprising in combination a main casing, an electromagnetic operating mechanism carried in said main casing, a diaphragm pos1t1oned in one end of said main casing, a supplemental casing supported from said mamcasmg and having a diameter and depth less than the diameter and depth of said main casing and a diaphragm carrled within said supplemental casing of smallersize than the diaphragm in said main casing and means whereby said electromagnetic operating mechanism operates both of said diaphragms for reproducing sound over a broad range of frequencies.

3. An electromagnetic sound reproducing apparatus comprising in combination a main casing, an electromagnetic operating mechanism positioned within said main casing, a diaphragm carried in one end of said main casing, a supplemental casing supported from said main casing, a diaphragm carried within said supplemental casing and differing in size from said aforementioned diaphragm, means whereby said electromagnetic operating mechanism operates both of said diaphragmsand means for simultaneously adjusting the distances between said electromagnetic operating mechanism and each of said diaphragms and selecting a 10 position at which sounds may be efficiently reproduced over a broad range of tone frequencies.

In testimony whereof I affix my signature.

MAURICE C. RYPINSKI. 

